Alkaline Rocks and Carbonatites of the World

Funded by HiTech AlkCarb - New geomodels to explore deeper for Hi-Tech critical raw materials in Alkaline rocks and Carbonatites

Bidu

stripes

Occurrence number: 
054-00-006
Country: 
Ethiopia
Location: 
Longitude: 41.5, Latitude: 13.28

Three large volcanoes, which from north to south are Nabro (2100 m), Mallahle (Mallali) and Asavyo (Mohr and Wood, 1976), are aligned along a north-northeasterly direction on the Danakil block. Each has a large summit caldera, that on Nabro being double with diameters of 10 and 5 km. Nabro and Mallahle comprise a complex strato-volcano which emitted very large volumes of rhyolitic products, mostly pyroclastics but some flows. Obsidian domes, pumice deposits and basaltic spatter cones and flows are located within and around the calderas, which they post-date. Many basaltic flows were emitted from fissures. Petrographic details of the rocks have not been found but the rhyolitic rocks are probably peralkaline.

References: 
BARBERI, F., CHEDEVILLE, E., FAURE, H., GIGLIA, G., MARINELLI, G., SANTACROCE, R., TAZIEFF, H. and VARET, J. 1973b. Geology of Northern Afar (Ethiopia) (with a geological map, scale 1:500,000). Revue de Geographie Physique et de Geologie Dynamique, Paris, 15: 443-89.
Location: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith